Hello Dr. Koregol, I have been having a pulsing sensation in my chest on the upper left side above my heart and below my shoulder blade for a few days. It is a very strong sensation. I don t always feel it, but when I do, it is very annoying. It feels kind of like my pulse , but it is very irregular and is not in tune with my heart beat, which seems normal. It does not hurt. It is, however, visible through my shirt, and you can easily feel it if you touch the area. I asked a friend to feel it earlier and they were a bit freaked out. I am starting to worry about this. What could it be? Thanks, Daniel